In various kinds of display devices, optical elements, semiconductor elements, building materials, automobile components and nanoimprint techniques, deposition of liquid droplets on a surface of a substrate may cause a problem of contamination and corrosion of the substrate, or further the deterioration in the performance due to the contamination and corrosion. Therefore, in these fields the substrate surface is required to have good water repellency. Particularly, it is required not only the prevention of deposition of liquid droplets on the substrate surface, but also the ease of removing deposited liquid droplets is required.
As a film capable of causing even a very small water droplet to slide down with a small inclination angle, Patent Document 1 proposes a film obtained by co-hydrolysis/condensation polymerization of an organosilane and a metal alkoxide in a solution containing an organic solvent and water.